where again the integral in the denominator ensures that the coefficient \({\cal M}\)  corresponds to the second moment (\(z\) -weighted integral) of the function.
In addition to the fragmentation to pions and kaons studied in earlier JAM analyses of SIA and SIDIS data [1]}, [2]}, here we consider also the inclusive production of unidentified charged hadrons, \(h^\pm \) .
Accounting for unidentified hadrons can be implemented in two ways.
First, the hadron FFs can be fit independently from those for pions and kaons, as preferred by the NNPDF Collaboration [3]}.
Alternatively, one can take advantage of existing knowledge of specified hadron FFs and add a fitted residual correction to their sum.
Such an approach was adopted by de Florian, Sassot, and Stratmann (DSS) [4]}, for example, in which a residual correction was fitted to the sum of previously obtained pion, kaon, and proton fragmentation functions.
